Fine pitch gold ball bonding optimization

Response surface methodology is used to characterize a state-of-the-art wire bonder with a bottleneck capillary for fine pitch bonding. Regression analysis generates mathematical models to plot 3-D charts and contour charts of ball size and ball shear force as a function of wire bond parameters. A procedure is described to use contour charts to optimize bonding parameters. Bonding windows are identified by using bonding specification requirements and material/process constraints as boundary conditions.<>